The effects of marriage and separation on the psychotropic medication use of non-married cohabiters: A register-based longitudinal study among adult Finns

Non-marital cohabitation has become increasingly common and is suggested to offer similar mental-health benefits as marriage does. We studied levels and changes in cohabiters' mental health five years before and five years after entering into marriage or separating, and compared long-term non-married and married cohabiters. We analysed changes in the three-month prevalence of psychotropic medication use (psycholeptics and psychoanaleptics, excluding medication for dementia) by proximity to non-marital transition and gender, using register data on 189,394 Finns aged 25 to 64. Similar levels of psychotropic-medication use were found among individuals in long unions that continued throughout the follow-up and were non-marital, marital, or changed from non-marital to marital. Among men and women who separated from longer cohabiting unions of more than five years, however, an increase in medication prevalence was observed immediately before separation, followed by a similar decline after separation. At the time of separation the level of medication use was 9.9 per cent (95% CI = 8.7 - 11.3) among men and 15.7 per cent (95% CI = 14.2 - 17.4) among women compared to 4.3 per cent (95% CI = 3.7 - 5.0) and 8.0 per cent (95% CI = 7.2 - 9.0), respectively, among those who cohabited continuously. No changes in medication use were observed before or after separation among those leaving shorter cohabiting unions of less than five years. Among those marrying following shorter cohabiting unions a positive effect of approaching marriage was observed only among women. Compared to continuous cohabiters, the level of medication use was higher among men and women separating from both short-term and long-term cohabiting unions five years before separation. This selective effect suggests that cohabiters with mental-health problems might benefit from relationship counselling. In a long-term stable union it seems to matter little for mental health whether the union is marital or non-marital, the break-up of a long-term non-marital union being strongly associated with adverse mental-health effects.